jkuokkala/ume-saami-conv: Orthography conversion for Ume Saami

Initial version of a conversion script, which implements a mechanical conversion from Wolfgang Schlachter's (1958) dictionary spelling into current Ume Saami orthography (approved 2016, dictionary by Henrik Barruk 2018).

The conversion has a number of known shortcomings partly due to the peculiarities of Schlachter's markup and source dialect. For instance some non-initial-syllable vowel conversions can not be automatized correctly due to syncope phenomena. The distinction between back /ï/ and front /i/ is not consistently deducible from Schlachter's spelling, so only /i/ is used here as well. Also the phoneme /đ/ (~ /r/) is represented by d in Schlachter and thus undifferentiable from a normal /d/.

The converted spelling is more detailed than the standard in that overlong geminates are marked with a straight apostrophe /'/, e.g. /beäg'ga/ ’storm’ (can be optionally turned off). The distinction between long (open) /å/ and short (closed) /o/, which is not marked in the standard orthography, can also optionally be retained. The superscript vertical line, which Schlachter occasionally uses to mark an elided (or overshort) vowel between 2nd and 3rd syllable, is converted to a curly apostrophe /’/.